Casting

Casting happens at two levels. One for built-in types and one for objects.

Built-in types casting

For built-in types, there are two types of casting.

1. Automatic casting when we cast from smaller to bigger data types. This is automatic because the smaller bits fits fully in the bigger type's allocated space.
2. Manual casting when we cast from bigger to smaller data types. In this case, only the last bits that fits in the smaller data type is retained.

Automatic widening

This is another type of casting that depends on the types involved in the arithmetic operation. The type of the result is automatically widened to the biggest type involved.

// char to int
c - '0' // Here the
//int to char
(char) '0' + n

Object casting

Object casting is different compared to built-in types casting and has different rules.

Understanding object layout

To build a great mental model, it's important to understand the object's memory layout. Only then we can understand how property values are inferred and functions are inferred